Four injured women, ranging in age from 22 to 40, were taken to Froedert Hospital. One victim was released from the hospital today, while the other three women remained in satisfactory condition, according to Kathy Sieja, hospital spokeswoman.

Randall Haughton Sr., who shares a name with his son, said this morning that he had spoken to his son recently and invited him to come to his home in Winter Garden, Fla.

"My home was always open for my children to return," the elder Haughton told ABCNews.com.

Police were called to the spa several weeks before the shooting because Haughton allegedly slashed the tires of his wife's car. He was arrested and charged for the incident, and later ordered to turn over all guns in his possession to the sheriff's department.

Investigators say they are still unclear why Radcliffe Haughton allegedly snapped, although they say he and his wife had been estranged for some time.

Witnesses say Zina Haughton's daughter, Yasmeen Daniel, 20, also worked in the spa and witnessed the shooting, which unfolded at 11:09 a.m. CST on Sunday.

"She had said her stepfather was in there trying to shoot as many people as he could," said Sallie Konruff, a witness at the scene.

Zina and Radcliffe Haughton have a 13-year-old daughter together, who was living with her father until the shooting, the source said.

It was the second mass shooting to rock the area in recent months, when Wade Michael Page, an Army veteran and white supremacist, killed six people and injured three others before fatally shooting himself at a Sikh temple south of Milwaukee.

For Pandeep Kaleka, the son of slain temple president Satwant Singh Kaleka, the memories are still raw, but he lent his support to victims as a grief counselor Sunday.

"You go to work every day and you don't expect something like that to happen," Kaleka said. "I reassured them it will change your perspective and you will try to get back to a normal routine but you'll always see the visions. The scars will get better but you are going to have to build your life around those scars."

Radcliffe Haughton Sr. apologized to the victims and their families for his son's apparent actions shortly after the incident.

"All I can say is, I want to apologize to the people of Milwaukee who have been hurt. He did not give me any hint of what he would do," Haughton told ABC News affiliate WISN-TV.

Haughton Sr. said his son was a former Marine whom he had not seen since sometime last year but spoke to him on the phone from time to time.

The shooting erupted 11:09 a.m. local time in Brookfield, and shortly after SWAT teams surrounded the spa with their guns drawn, preparing for a gun battle.

Witnesses described screaming women, at least one bleeding, fleeing the spa, with one rolling down a slight hill before police scooped her up and got her out of the area.

Customers -- some still in robes, others barefoot -- ran out of the spa in a panic. John Gosh came face-to-face with the shooter as he tried to escape.

"When the suspect came around the corner, he really looked like a deer in headlights. He didn't expect us to be standing there. He just ducked behind the building," Gosh said.

Chief Tushaus said police rescued up to 12 clients and employees when they first arrived and began a painstaking search of the 9,000-square-foot building that includes two floors. The chief said the building included many treatment rooms, often locked.

"We were expecting an armed encounter," Tushaus said.

A "be on the lookout" alert was issued for Haughton and hours later, a black 2003 Mazda driven by the suspect was recovered outside of Brookfield, but police declined to say where it was found.

Tushaus said police believe the gunman took a taxi to the spa.

Authorities swarmed Haughton's home in the suburb of Brown Deer, and sent in a robot to search the residence, ABC News' affiliate WISN reported.

The Westmoor Country Club, which shares a parking lot with the spa, was put on lockdown along with other businesses in the area, the club's chief operating officer, Joe Coen, said.

"We didn't hear anything but ventured to the north toward the spa and we could clearly see police officers with what looked like to be a rifle and a few attendants were coming out of the building," he said. "We quickly retreated back to the building where authorities have told us to stay."

Wisconsin Gov. Scott Walker pledged his support for the victims and the community.

"Senseless acts of violence leave us with heavy hearts and many questions," Walker said in a statement. "Our state will stand with the victims and their families, and we will provide them with the law enforcement and community support they need to heal in the coming days."